Project Summary. Serious suicide attempts (those requiring an emergency department visit) among adolescents in the United States have soared 65% over the past five years (CDC, 2015), alarming public health officials. One major concern is the long-term health prognosis of these suicide-attempting adolescents: International research suggests they may be at exceptionally high risk for lifelong excess healthcare needs, impairment, and health-related economic strain (Goldman-Mellor et al. 2013, Herbert et al. 2015). Equivalent data from the U.S., however, are lacking ? leaving clinicians and public health officials in the dark about how best to prevent adverse health outcomes among our nation?s suicidal youth. The current study will address this gap by providing clinically relevant information about long-term patterns of healthcare utilization, morbidity, and healthcare costs among adolescent suicide attempters in the nation?s most populous state. The project has three specific aims: (1) To investigate long-term patterns of emergency department (ED) visits, hospital inpatient stays, morbidity risk, and healthcare costs among adolescent suicide attempters relative to controls; (2) To investigate factors predicting worse outcomes among suicide attempters; and (3) To engage graduate and undergraduate students in using administrative healthcare data to conduct epidemiologic research on adolescent suicidal behavior. To accomplish these aims, the project will use state-level hospital data from California to identify all adolescent patients who sought ED care for an index suicide attempt in 2010. We will capitalize on the state?s longitudinal record linkage capabilities to follow this cohort of suicide attempters for 6 years ? across institutions and across the state ? and compare their rate of later ED and hospital visits, risk for specific injuries and illnesses (including suicide attempt, assault injury, and complications of chronic disease), and ED/ hospitalization costs with those of matched non-suicidal controls. The project will also test whether adolescent suicide attempters with greater baseline clinical, social, or psychological vulnerability exhibit worse risk of adverse health outcomes. This study will comprise the largest population-based follow-up analysis of young suicide attempters in the U.S., and provide the first estimates of these youths? long-term health, healthcare utilization, and economic risks. Results from this project will help guide future intervention efforts among suicidal youths to reduce their lifelong morbidity and costs, contributing directly to the goals of NICHD?s Pediatric Trauma and Critical Injury Branch (PTCIB). By shedding light on suicidal adolescents? future risk of not just self-harm but a broad range of injury- and disease-related outcomes, this work will improve the effectiveness of clinical care, facilitate risk stratification, and aid in the allocation of scarce healthcare resources for a vulnerable and growing population of young people. Moreover, the project will enhance research capacity by fostering a new pipeline of student health researchers from underrepresented groups and by creating a significant new data resource for the field of adolescent health.